//
// detail/blocking_executor_op.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_DETAIL_BLOCKING_EXECUTOR_OP_HPP
#define ASIO_DETAIL_BLOCKING_EXECUTOR_OP_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"
#include "asio/detail/event.hpp"
#include "asio/detail/fenced_block.hpp"
#include "asio/detail/handler_invoke_helpers.hpp"
#include "asio/detail/mutex.hpp"
#include "asio/detail/scheduler_operation.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
    namespace detail {

        template<typename Operation = scheduler_operation>
        class blocking_executor_op_base : public Operation {
        public:
            blocking_executor_op_base(typename Operation::func_type complete_func)
                    : Operation(complete_func),
                      is_complete_(false) {
            }

            void wait() {
                asio::detail::mutex::scoped_lock lock(mutex_);
                while (!is_complete_)
                    event_.wait(lock);
            }

        protected:
            struct do_complete_cleanup {
                ~do_complete_cleanup() {
                    asio::detail::mutex::scoped_lock lock(op_->mutex_);
                    op_->is_complete_ = true;
                    op_->event_.unlock_and_signal_one_for_destruction(lock);
                }

                blocking_executor_op_base *op_;
            };

        private:
            asio::detail::mutex mutex_;
            asio::detail::event event_;
            bool is_complete_;
        };

        template<typename Handler, typename Operation = scheduler_operation>
        class blocking_executor_op : public blocking_executor_op_base<Operation> {
        public:
            blocking_executor_op(Handler &h)
                    : blocking_executor_op_base<Operation>(&blocking_executor_op::do_complete),
                      handler_(h) {
            }

            static void do_complete(void *owner, Operation *base,
                                    const asio::error_code & /*ec*/,
                                    std::size_t /*bytes_transferred*/) {
                blocking_executor_op *o(static_cast<blocking_executor_op *>(base));

                typename blocking_executor_op_base<Operation>::do_complete_cleanup
                        on_exit = {o};
                (void) on_exit;

                ASIO_HANDLER_COMPLETION((*o));

                // Make the upcall if required.
                if (owner) {
                    fenced_block b(fenced_block::half);
                    ASIO_HANDLER_INVOCATION_BEGIN(());
                    asio_handler_invoke_helpers::invoke(o->handler_, o->handler_);
                    ASIO_HANDLER_INVOCATION_END;
                }
            }

        private:
            Handler &handler_;
        };

    } // namespace detail
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // ASIO_DETAIL_BLOCKING_EXECUTOR_OP_HPP
